Issue #27517: LZMA compressor and decompressor no longer raise exceptions if

given empty data twice.  Patch by Benjamin Fogle.
This commit is contained in:
Serhiy Storchaka 2016-10-31 08:30:09 +02:00
parent 0bcd89b859
commit 04f17f103a
4 changed files with 47 additions and 0 deletions

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@ -136,6 +136,21 @@ class CompressorDecompressorTestCase(unittest.TestCase):
self.assertTrue(lzd.eof)
self.assertEqual(lzd.unused_data, b"")
def test_decompressor_chunks_empty(self):
lzd = LZMADecompressor()
out = []
for i in range(0, len(COMPRESSED_XZ), 10):
self.assertFalse(lzd.eof)
out.append(lzd.decompress(b''))
out.append(lzd.decompress(b''))
out.append(lzd.decompress(b''))
out.append(lzd.decompress(COMPRESSED_XZ[i:i+10]))
out = b"".join(out)
self.assertEqual(out, INPUT)
self.assertEqual(lzd.check, lzma.CHECK_CRC64)
self.assertTrue(lzd.eof)
self.assertEqual(lzd.unused_data, b"")
def test_decompressor_chunks_maxsize(self):
lzd = LZMADecompressor()
max_length = 100
@ -273,6 +288,16 @@ class CompressorDecompressorTestCase(unittest.TestCase):
lzd = LZMADecompressor(lzma.FORMAT_RAW, filters=FILTERS_RAW_4)
self._test_decompressor(lzd, cdata, lzma.CHECK_NONE)
def test_roundtrip_raw_empty(self):
lzc = LZMACompressor(lzma.FORMAT_RAW, filters=FILTERS_RAW_4)
cdata = lzc.compress(INPUT)
cdata += lzc.compress(b'')
cdata += lzc.compress(b'')
cdata += lzc.compress(b'')
cdata += lzc.flush()
lzd = LZMADecompressor(lzma.FORMAT_RAW, filters=FILTERS_RAW_4)
self._test_decompressor(lzd, cdata, lzma.CHECK_NONE)
def test_roundtrip_chunks(self):
lzc = LZMACompressor()
cdata = []
@ -283,6 +308,19 @@ class CompressorDecompressorTestCase(unittest.TestCase):
lzd = LZMADecompressor()
self._test_decompressor(lzd, cdata, lzma.CHECK_CRC64)
def test_roundtrip_empty_chunks(self):
lzc = LZMACompressor()
cdata = []
for i in range(0, len(INPUT), 10):
cdata.append(lzc.compress(INPUT[i:i+10]))
cdata.append(lzc.compress(b''))
cdata.append(lzc.compress(b''))
cdata.append(lzc.compress(b''))
cdata.append(lzc.flush())
cdata = b"".join(cdata)
lzd = LZMADecompressor()
self._test_decompressor(lzd, cdata, lzma.CHECK_CRC64)
# LZMADecompressor intentionally does not handle concatenated streams.
def test_decompressor_multistream(self):

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@ -446,6 +446,7 @@ Frederik Fix
Tom Flanagan
Matt Fleming
Hernán Martínez Foffani
Benjamin Fogle
Artem Fokin
Arnaud Fontaine
Michael Foord

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@ -113,6 +113,9 @@ Core and Builtins
Library
-------
- Issue #27517: LZMA compressor and decompressor no longer raise exceptions if
given empty data twice. Patch by Benjamin Fogle.
- Issue #28549: Fixed segfault in curses's addch() with ncurses6.
- Issue #28449: tarfile.open() with mode "r" or "r:" now tries to open a tar

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@ -527,6 +527,8 @@ compress(Compressor *c, uint8_t *data, size_t len, lzma_action action)
Py_BEGIN_ALLOW_THREADS
lzret = lzma_code(&c->lzs, action);
data_size = (char *)c->lzs.next_out - PyBytes_AS_STRING(result);
if (lzret == LZMA_BUF_ERROR && len == 0 && c->lzs.avail_out > 0)
lzret = LZMA_OK; /* That wasn't a real error */
Py_END_ALLOW_THREADS
if (catch_lzma_error(lzret))
goto error;
@ -906,6 +908,9 @@ decompress_buf(Decompressor *d, Py_ssize_t max_length)
PyObject *result;
lzma_stream *lzs = &d->lzs;
if (lzs->avail_in == 0)
return PyBytes_FromStringAndSize(NULL, 0);
if (max_length < 0 || max_length >= INITIAL_BUFFER_SIZE)
result = PyBytes_FromStringAndSize(NULL, INITIAL_BUFFER_SIZE);
else